Sentry left stony broke and the author is responsible for this (4)
I believe the answer is:
book
This could be a double definition.
'sentry left' is the first definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'stony broke and the author is responsible for this' is the second definition.
The definition suggests a singular noun which matches the answer.
Can you help me to learn more?
(Other definitions for book that I've seen before include "Reading volume" , "Reserve - publication" , "Reserve - something to read" , "Written work; reserve" , "See 1 ac" .)